Greenpeace criticized Amazon’s renewable energy strategy again, in May - and since then, Amazon has signed a large solar energy contract. More importantly, it has made a very rare public response to the environmental campaign group’s argument.

The latest “Clicking Clean” report from Greenpeace (in May) gave Amazon an F for energy transparency and a D for “renewable energy deployment and advocacy”. Amazon has in fact promised to move to all-renewable sources, but hasn’t issued a roadmap stating when and how this will happen.

But this last week saw Amazon signing to pay for an 80MW solar farm in Virginia. Amazon will pay solar provider Community Energy to build it, and buy all its output - enough to power several Amazon data centers.

Buying solar 

It’s the second “power purchase agreement” from Amazon this year, following a deal to buy a 150MW wind farm in Indiana.  Amazon now has something like 25 percent of its energy from renewable sources, and expects to reach 40 percent by the end of 2016.

Amazon also broke its official silence in response to Greenpeace, when Jeff Barr blogged a response to the Clicking Clean report earlier this month. Greenpeace is hitting the wrong target, says Barr, because the best way to cut carbon emissions is to move loads from inefficient enterprise servers onto the cloud.

He is expanding on some points made earlier in a personal capacity by James Hamilton, distinguished engineer and vice president at Amazon. “The greenest power is that which is not consumed,” says Hamilton, and the best way to consume less power is to use it more efficiently.

Is in-house IT the bad guy?

While Greenpeace attacks big names, it’s missing the places where IT power is wasted, say Barr and Hamilton. The data center market is pretty well understood, and reports like the DatacenterDynamics Global Market Overview make it pretty clear that big cloud providers like Amazon still only make up a fraction (say five percent) of the IT industry’s power demand.

Most of the power is used by in-house servers and data centers. Since these operate at utilization of between 10 and 20 percent, in facilities with a PUE of 2.0 or more, the industry could save emissions hugely by moving these onto the cloud, say Hamilton and Barr.

Loads moved onto the Amazon cloud consume 77 percent fewer servers, says Barr, because utilization is higher. They also use 84 percent less energy, because those servers are being run in more efficient facilities.

And finally, they produce 88 percent less carbon - because the amount of renewable power used by Amazon is already above average.

In other words, take into account the huge amount of inefficient (and sometimes comatose) servers out there in corporate data centers, and the cloud provides such a huge improvement, it would reduce carbon impact, even if it were powered entirely by fossil fuels, which - as Barr points out - it never would be.

So what does this mean to data center people.

Firstly, this could be a gigantic marketing plus for Amazon. The company is telling us that customers who move into its welcoming cloud are not only saving their own time and money, they are saving the planet too.

It’s not that simple, of course. But when cloud is marketed this way, in-house data center people had better have some good energy use figures and projections as an alternative. 

A version of this article appeared on Green Data Center News.